/Engine/Source/Editor/UnrealEd/Public/Subsystems/PanelExtensionSubsystem.h
[FPanelFactoryRegistryChanged](API\Editor\UnrealEd\Subsystems\UPanelExtensionSubsystem\FPanelFactoryReg-) & OnPanelFactoryRegistryChanged ( [FName](API\Runtime\Core\UObject\FName) ExtensionPanelID )